Experiences with Alternative Electron Acceptors in the Large-Scale In-Situ Bioremediation of Aromatic Hydrocarbons

The groundwater beneath an abandoned refinery site is highly polluted with aromatic hydrocarbons. After removal of the free phase by hydraulic measures the immobile residual concentration located 6–10 m beneath the surface is still present and causes hydrocarbon concentrations from 10 to 100 mg/1 in the groundwater. The area of water pollution is about 20 ha whereas the residual saturations are covering an area of 7 ha. Because of the deep location of the contaminants beneath the surface and the good hydraulic conditions in-situ bioremediation was the appropriate method.